/*
 * Copyright (c) 2011-2014 Pivotal Software, Inc.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package org.camunda.bpm.extension.reactor.projectreactor.io.codec;


import java.util.function.Consumer;
import java.util.function.Function;

/**
 * A simple {@code Codec} that uses the source object as both input and output. Override the {@link
 * #beforeAccept(Object)} and {@link #beforeApply(Object)} methods to intercept data coming in and going out
 * (respectively).
 *
 * @author Jon Brisbin
 * @author Stephane Maldini
 */
public class PassThroughCodec<SRC> extends Codec<SRC, SRC, SRC> {
  @Override
  public Function<SRC, SRC> decoder(final Consumer<SRC> next) {
    return new Function<SRC, SRC>() {
      @Override
      public SRC apply(SRC src) {
        if (null != next) {
          next.accept(beforeAccept(src));
          return null;
        } else {
          return beforeAccept(src);
        }
      }
    };
  }

  @Override
  public SRC apply(SRC src) {
    return beforeApply(src);
  }

  /**
   * Override to intercept the source object before it is passed into the next {@link Consumer} or
   * returned to the caller if a {@link Consumer} is not set.
   *
   * @param src The source object.
   * @return
   */
  protected SRC beforeAccept(SRC src) {
    // NO-OP
    return src;
  }

  /**
   * Override to intercept the source object before it is returned for output.
   *
   * @param src
   * @return
   */
  protected SRC beforeApply(SRC src) {
    // NO-OP
    return src;
  }

}
